This is intended to be an almost non-verbal exercise.
In this scenario there are likely to be police or security guards close by. So the proposal process and hand-signals will allow for speed and privacy.
Remind people that there will have been an action briefing beforehand and so to focus on the decision-making process rather than the value of the action.
Depending on numbers and timings you can place people in breakouts of about 6.
You can ask for feedback about the process first, and the decision they made if you have time.
